Mechanics questions | form five Physics

1. Why the value of acceleration due to gravity (g) changes due to the change in latitude? Give two reasons.
2. A rocket is fired from the earth towards the sun. At what point on its path is the gravitational force on the rocket zero?

1. Define torque and give its S.I. unit.
2. A disc of moment of inertia 2.5×10^-4​ kgm² ​ is rotating freely about an axis through its centre at 20​ rev/min. If some wax of mass 0.04​ kg is dropped gently on to the disc 0.05​ m from its axis, what will be the new revolution per minute of the disc?

Explain briefly why a:

1. high diver can turn more somersaults before striking the water?
2. dancer on skates can spin faster by folding her arms?

A heavy flywheel of moment of inertia 0.4​ kgm ​ 2 is mounted on a horizontal axle of radius 0.01​ m . ​ If a force of 60​ N ​ is applied tangentially to the axle:

1. Calculate the angular velocity of the flywheel after 5 seconds from rest.
2. List down two assumptions taken to arrive at your answer in (i).

1. list down two main assumptions in deriving the equation of projectile motion.
2. Why the horizontal motion of a projectile is constant?

A ball is thrown horizontally with a speed of 14.0ms^-1 from a point 6.4 m above the ground. Calculate:

1. The horizontal distance traveled in that time
2. Its velocity when it reaches the ground.

A man stands in a lift which is being accelerated upwards at 3.2m/s². If the man has a mass of 65kg. What is the net force exerted on the man by the floor of the lift?

Why is it technically advised to bank a road at corners?

A wheel rotates at a constant rate of 10 revolutions per second. Calculate the centripetal acceleration at a distance of 0.80 m from the centre of the wheel.

1. With the aid of a labeled diagram, sketch the possible orbits for a satellite launched from the earth.
2. From the diagram in (i) above, write down an expression for the velocity of a satellite corresponding to each orbit.